NASA yesterday issued a revised set of dates for 2008 shuttle launches after a meeting to "evaluate options following the STS-122 [Atlantis] mission delay", the agency reports.
STS-123 on Endeavour and STS-124 on Discovery are slated for lift-off on 11 March and 24 April, respectively, although "any decision on those launch …

Leave them in space

If they are abandoning the shuttles why don´t they leave them in space and use it as a shuttle to/from moon or simply acopled to the ISS. It would be better than rusting on earth. (sorry for the english).

Leave Em?? Not Possible

Well, the shuttle was never designed to stay in orbit perminantly. It uses consumables at a steady rate and when they run out, the shuttle's systems will shut down. The ISS on the other hand is designed to say up for an extremely long duration and it's consumables are used at a much slower rate, with top-ups coming via the shuttle and the progress supply craft.

Also while the shuttle is attached to the station the shuttle helps keep the station in correct orbit and orientation since the added mass of the shuttle to the structure changes the mass and center of gravity and the ISS's orbit and attitude control systems can't cope. Once the shuttle (if it were to become a perminant fixture) ran out of supplies, it could no longer help keep the station in correct alignment. Also, the shuttle isn't capable (as far as I know, im not a Chinese contractor ;P ) of having it's OMS fuel supply topped-up in orbit.

The shuttles wouldn't exactly rust if they were to retire on the ground. The Smithsonian will get one to keep in perfect climate-controlled condition, and as they start to be taken offline, they will be used as spare parts for the ones still flying. Pretty undignified way to retire if you ask me!

Leave them in space

I debated about responding to this, but the comments are more innocent than the normal sort of affair suggesting technical impossibilities, so I'll bite.

The 1st and foremost problem is the fuel cells. One of the most recent examples of throwing good money after bad is a MANY $$$$$$$$$ "upgrade" to power the shuttle systems from the ISS solar power. This saves USING the fuel cells and extends the time a shuttle can spend at the station. However, it is not possible to prevent the fuel cells from leaking.

(Examples:

1) Once cells are fueled on the pad the shuttle must launch within 5 days or a day off is taken to top off tanks, most notably the fuel cells.

2) On a related note the US lost Skylab - an arguably more capable platform than ISS - because the last Apollo mission was left up too long and NASA was afraid this same leakage, this time of SM propellant, would prevent Apollo from BOTH raising the orbit of skylab AND successfully de-orbiting.

3) I beleive propellant leak down is also why the Soyuz capsules can only stay at ISS for 6 months.)

Back to our story, without fuel cells the shuttle has no electrical power at all and is a big ceramic meteor. NEXT as was pointed out is the OMS engines. The 2 small(ish 10K lbs thrust) restartable engines in the pods at the rear. These are used for circularizing the initial orbit, raising ISS, and de-orbit burns. WAY back in the 70s plans were for expansion tanks of OMS fuel in the cargo bay. Back then the shuttle was planned to stay up a month or more and drive around all over orbit. Sadly one thing people don't realize is changing an orbit is GHASTLY expensive in fuel and from a practical perspective cannot be done.

OMS (ironically named Orbital Maneuvering System - even though we just showed they in fact can't really maneuver at all) fuel reserves are virtually non-existent and there is no possibility to refuel. RCS (reaction control system - steering) fuel, while not as dire as OMS supply is also VERY limited.

The above I am certain of. Another area of concern is the APUs which perform adequately at providing hydraulic power for the areosurfaces in the atmosphere. However they are at their design limit there and it seems certain fuel leakage or just plain old entropy would be a problem in short order. There were also problems with coolant lines freezing when they did start powering down to run off ISS power. This may be solved, or it may not. I don't know. But it became clear you can't just hit the big red button and turn it on in a few months / years later.

---

As far as the moon goes, the shuttle lacks by MANY times the amount of fuel (read delta-V) to escape earth orbit. If it did so, it then would lack the fuel needed for Lunar orbit insertion. The result would be a quite unsatisfactory sling shot into deep space.

There are MANY other problems far too serious and numerous to list here, but basically building a new ship would be orders of magnitude cheaper than trying to lift a shuttle out of earth orbit.

Leave them in space III

Well (as someone who has had the pleasure of working with the Shuttles in the past) as said before, the shuttles aren't equipped for onorbit resupply. Besides crew consumables, there are the cryogenics for fuel cells, hydrazine for thrusters and OMS. It might be possible to work out some method to do so, but currently there is no ability. If I remember correctly the tanks assume 1G for tanking, so it might not work.

Orbits: The shuttles would have to be placed in high enough orbits so they wouldn't reenter and burn up after a couple of years. The ISS orbit is too low for this, that's why it requires periodic reboosts. Hubble's orbit is high enough, and certainly the shuttles can make it that high as a shuttle was used to place it there in the first place... Something to keep in mind is that NEO (Near Earth Orbit) isn't a benign place. Highly reactive monatomic Oxygen and Hydrogen are constantly attacking surfaces, as well as micrometeorites and space junk. Satellites intended to stay aloft for a long time are better protected to such then the shuttles, so the vehicles may not be terribly useful after a couple of years on orbit.

Dumping Shuttles in Space

There is already another thread here on El'Reg discussing this daft idea... and it just can't work. A Shuttle is not like a car when it runs out of fuel. It's not a simple case of just sitting there with an empty fuel tank.

Ditto it can't be used to fly to Mars as some daft ideas try to suggest... :)

shuttle between earth and moon

As Robert says, I guess the biggest problem of using the shuttle as a space tug ( apart from the fact the EU is doing one ) is that the shuttle is designed to be serviced between missions on the ground.

I bet it's got thousands of small screws / parts that need to be moved between missions, like screws for hatches etc. Not an easy task in space. The space dock idea is a good few years off.

But a moon / earth shuttle is a good idea, it's been around for a while I seem to remember, one day..

Shuttle

Using it as a space-only travel pod would mean spending enormous amounts of fuel to drag around inert launch engines, wings, tail, control surfaces, landing gear, unremovable living space, etc. etc. etc. Things you can't just pop off in orbit.

The space shuttle is not an efficient travel pod, not by a long shot; it's a lab, a LEO construction platform, a satellite deployment system, a FUNCTIONAL GLIDER, etc. etc. etc. but not a travel pod.

We have such a thing available anyway, the Soyuz, that IS designed to carry people to the Moon and back, to zip around to places in orbit, hang out at a space station for six months, and more.

Thanks to a few legal tweaks by congress a few years back, NASA can buy these wonderful travel pods at a price that's spare change compared to the shuttle.

Obviously the shuttle is great for a lot of things, but these are very different roles and the Shuttle as a travel pod would work as well as trying to use the Soyuz to build a space station or run a seven-person lab for two weeks.

You wouldn't take a 747 to a dogfight either. Some things just aren't meant to be.